Vehicle drive



May7,1935l F. R. HIGLEY 2,000,465

VEHI CLE DRIVE Filed Jan`- 20, 1933 2 Sheets-Sheet 1 INVENTOF 2. I ATTORNEY:

May 7, 1935.

Filed Jan. 20, 1935 2 Sheets-Sham 2 6 R m O E i 4 f a a m ,r 5 x o f M m- R. n K N m m MM 6 w( QG Patented May 7, 1935 2,000,465

UNITED sTATEs PATENT OFFICE VEHICLE DRIVE Frank B. lllgley, Clevehnd Heights, Ohio Applicationrlanuary 26, 1933, Serial No. 652,669 17 Claims. (Cl. 172-239) 'lhis invention relates to means for transthis illustration, the load to be, driven by the mitting the power of an internal combustion engine. v engine or the like, to its load, the engine being G is an electrical generator arranged to be .in operation. and the load beingk a variablerone continuously driven by the engine as by the tube driven at -various speeds from a standstill direct connection indicated. The capacityof l condition. the generator 'is substantially less than that of The invention contemplates the combination the engine, say one-third; and the generator is of an' engine. a generator constantly driven preferably of shunt characteristics, may be comthereby, a motor to be driven by the generator, pound wound, and providedy with a rheostat I and differential gearing between the engine, the and associated voltmeter 2 whereby its neld l0 motor and the load, whereby the load is difexcitation may be controlled through the conferentially driven. nections indicated, as will be well understood The objects of the invention are to simplify the by one familiar with the art. operation of` the parts and particularly their D represents generally a differential gearing control by the operator, and to make the aphere shown as having an input element 3 in the- 15 paratus function substantially automatically in form of a pinion, an output element 4 in the coordinating the speeds of the engine and motor form of a gear, gears 5 meshing with the pinion 'with respect to the load. 3, pinions 6 meshing with the gear l, and a sec- The invention is particularly applicable to fond input element l hereshown as peripherally 2o self-propelled vehicles having a type of drive grooved to serve as a pulley. Each gear 5 and 20 ysuch as that shown in my copending applicaits pinion 6 are secured together against rotation. Serial No. 650,959, iiled January 10, 1933, tion, mounted on a shaft 6 carried by the pulley in which the traction wheels comprise the load 'I and free to rotate in the latter. The arrangeto be driven by the engine of the vehicle. In ment indicated will be recognized as one wheresuch a vehicle application the objects of this in the gear 4, the output element of the difleren- 25 invention are to provide superior control of tial D, is differentially driven by both the nrst locomotion. input element, the pinion 3, and the second input 'I'he exact nature of the invention, togetherl element. the pulley 1; and it Will be underStOOd with further objects and advantages thereof will that the parts` are munted in Suitable bea-rings be apparent from the following description taken for the purpose. fOr exrnple that the elements 30 in connection with the accompanying drawings, 3, 1 and 4 are mounted for alignment but indewhich are largely diagrammatic and otherwisek pendent rotation as in the usual differential arconventionalized showings of elementaryv emrngementbodiments of the invention, and in which more The input element 3 iS arranged t0 be driven nnrtieninriy Fig i represents the prineipei (1i-ivby theengine subject to engagement of a clutch 35 ing elements of a vehicle in which the invention C Controlled by a lever 9- is embodied, the arrangement being one for full The SeCOnd input element 1 iS arranged t0 be automatic control of the transmission means; driven by a motor' M, the drive being here pig. 2 is a detail View iiinstrating the pertinent shown conventionally as through the belt Il.

40 parts of a modification of the arrangement indi- The prODOrtiOn und arrangement 0f the pl'tS 40 cated Fig i, the arrangement being one in is preferably such that the leverage of the mowhich manual control of the transmission means tOr M upon the Output element 4. With respect 'is had: .pig 3 Ais n mndinention of the arrangeto the leverage of the input element 3 on the ment shown in Fig '1, also for fun automatic output` element, is in inverse 'ratio to the power operation; Fig 4 is `another modncation pro.. 0f the motor M, l'elatin t0 the power 0f 45 ding for low voltage contr-oi, and pig. 5 is e the engine E less that of the generator G. sectional detail of the overrunning clutch means The Output Clement l 0f the differential, in appearing in pig 1. 4 the case of a vehicle as chosen for illustration,

with reference new to the form iinstrated is connected to a reverse gear R as by the shaft i0 pig il E is the engine and w are the wheels 29. A drive shaft I2 is arranged to be driven 60 te be driven thereby, it being understood that by the reverse gear R and to drive the axle A these are parts of a vehicle, associated by the on which the traction wheels W are mounted. usual frame, etc., not illustrated as being well The reverse gear R is controlled as by a lever known in the art and forming no part of the Il, and it will be understood that there are three present invention. Thewheels thus comprise, in conditions of the reverse gear parts with corresponding positions of the lever Il: a forward one wherein the shaft I2 will be driven in the same direction and preferably at the same speed as the gear 4; a reverse one in which the shaft I2 will be driven by the gear 4 but in the opposite direction; and a neutral position interwhich there will be no driving connection from shaft 29 to shaft I2. The lever II is shown as in the neutral position.

The motor M is preferably of series type, approximately the capacity of the generator G, and is arranged to be driven by the generator, through the circuit indicated including a controller i3, line 45 leading from generator to controller, line M from controller to motor, and line d8 from motor to generator. The motor control need not include means for reversing the motor, and the arrangement is such that the motor will drive its differential input element only in a direction corresponding to that in which the other diierential input element is driven by the engine. In other words, both engine and motor, and their dierential input elements are arranged to have unidirectional driving effect upon the diiTerential outputelement. Means are associated with the motor-driven differential input element 'I to prevent drive of that element in reverse direction by the other differential elements. Such means are here indicated as an overrunning or one-way clutch Il, having one of its members xed as by the arm I5, its other member secured with the motor shaft, and means between the members providing that the motor is free to operate in its forward direction but its armature may not be rotated in the reverse direction. Such a clutch is old and well known in the art and has recently found extensive use to provide the .so-called free-wheeling in the automotive industry. The elementary arrangement of the clutch is indicated in the fragmentary View thereof immediately below its showin/gat I4.

The engine E has throttle means which may be governor-controlled to x the engine speed as is well understood in the art, or which may be arranged for hand control. The latter arrangement is indicated as to the throttle I6; and a governor may be arranged to control a second throttle 26, responsive to engine speed, to prevent overspeeding of the engine.

The controller I3 is here shown as arranged for automatic operation responsive to the speed of the load. The load here constituting the wheels vW, the controller is actuated responsive to the speed of the vehicle. To this end a governor indicated at 2'I having a drive 28 as from the shaft 29 which connects the differential output element 4 with the reverse gear R, is connected with the contactor arm 30 of the controller I3, as by a rock shaft 3|. The proportioning and arrangement of the parts is such that when the vehicle is stationary, the contactor arm 30 of the controller I3 will be off the indicated resistance of the controller, so that the motor M will not receive power from the generator G; and in fact will not receive power from the generator until the load has attained a certain substantial minimum speed; after which the contactor 30 will make a connection with the resistance to cut the motor into the generator circuit, and will gradually cut out resistance as the vehicle speed increases.

It being preferable that the voltage output of the generator G be maintained fairly conland consequently the vehicle, stationary.

stant, and to this end, particularly if the engine is to be hand-controlled, a governor 32 may be arranged as by a connection 33 to control the contacter arm 34 of the ield resistance i of the generator, responsive to the speed of the generator as by a connection 35 arranged to drive mediate the forward and reverse positions in' the governor 32.

Operation will be as follows assuming the parts as indicated, the engine running at idling speed, the clutch C released, the reverse gear R in neutral position, the controller I3 maintaining the motor circuit open, and the wheels W, To advance the vehicle the reverse gear R is set for forward operation, by shifting its lever II. The clutch C is next engaged by manipulation of the lever 9, preceded by opening of the throttle I6 either at least sufficiently to prevent stalling of the engine or entirely, to release the engine to the control of the governor 25. Engagement of the clutch causes the engine to drive the input element 3 of the diierential D. The element lI' of the differential is iixed against reverse rotation, by the one-way clutch I4. Consequently the diierential output element I is4 driven at low speed through the gears 5, pinions 6 and their connecting shafts 8. This low speed drive is transmitted to the wheels W through the reverse gear, drive shaft and axle, and the vehicle consequently advances, positively driven directly from the engine through the speed reduction provided by the differential under the described condition. There is no expenditure of energy driving the generator, as there is no load on the latter, the motor M being disconnected. The clutch C being engaged the wheels will turn and the vehicle advance at a speed in direct proportion to the engine speed.

Ultimately the engine speed increases, as the vehicle gets under way, and unless the throttle means is sooner closed. When the vehicle speed has increased to a point where the motor M may effectively act, the governor'ZI, being responsive to vehicle speed, automatically moves the contactor 30 of the motor controller I3, to connect the motor with the generator, with the controller resistance in circuit. The motor then drives the second differential input element 1 to increase the speed of the differential output element 4 more than proportionally to that of the input element 3. The drive from engine to wheels is now partly by way of the generator G, motor M and diierential D, as well as from the engine by way of the clutch C and the differential.- caused to increase, the governor 21 gradually shifts the controller I3 to cut out resistancev from the motor circuit, until ultimately the motor is connected directly with the generator with no resistance in circuit. By this time the motor speed has increased up to the point where its input element 1 of the. diierential is rotating at substantially the speed of the input element 3 of the differential so thatall of the diiierential gears are stationary with respect to each other, all moving as a unit about the common center.

Meanwhile the generator voltage has been maintained by the governor 32 acting upon the eld controller I. Also the engine speed has attained that permitted by the governor 1i or the hand throttle means. the drive from 'engine to wheels is now sub stantially direct, the shaft I2 moving at engine speed. In the latter event the vehicle is moving As the vehicle speed is thus` In the former event A as fast as permissible at that engine speed and load condition. l

This running condition is substantially maintained so long as the engine throttle I6 is maintained open. I! the vehicle meet with increased resistance to locomotion as on ascending a hill, the motor M, having series characteristics, will be slowed down somewhat and the differential gearing will permit some slip, allowing the engine to continue running and maintain the vehicle in locomotion. If the vehicle speed is materially decreased by this action of the differential the governor 21 will reset the controller I3 to prevent overloading of the motor M, and maintain the differential action proper for best efficiency of both engineand motor. If the vehicle `slows sufficiently, the motor will bei` automatically cut out of circuit, releasing the engine to drive the load wholly mechanically.

Also, should the load resistance decrease, as

on descending a hill, the engine speed may be reduced by manipulation of the throttle without functioning of the governor 21 to cut resistance into\th\e motor circuit, provided the vehicle speed be maintained.

At anv time the vehicle speed may be reduced by closing the hand throttle I6 to reduce the engine speed.

Operation in reverse will obviously be the same except that the lever Il will be set in reverse position before engagement of the clutch C.

It will be observed that so far as the operator is concerned, once the reverse gear is set for the desired direction of travel, all that is necessary to govern the vehicle speed. is manipulation of the hand throttle I6, and in any event in starting, once the clutch C is engaged drive will be first positive and thence partly electrical, automatically dependent upon relation of engine speed to the load.

In the modification of Fig. 2, the general arrangement of the principal parts is similar to that indicated in Fig. l with the exception that the engine speed is maintained constant, wholly under governor control, the motor controller is arranged for manual instead of governor operation, and a common handle is provided for operating both the controller and the clutch C. It, therefore, being understood that parts and arrangement not appearing in Fig. 2 are the same as those appearing in Fig. 1, the clutch C is arranged for operation by a lever 40, pivoted at 4I and is normally maintained in engagement as indicated by the compression spring 42. A handled lever 43 pivotally mounted at 4I yhas a part 44 adapted to engage the clutch lever 4l for clutch-releasing actuation of the latter against the effect of the spring 42. The lever s43 is free to move in the opposite direction, bevyond the lever 4I in that position thereof in which the clutch is engaged. The lever 43 is connected with the generator-controller line 45 and arranged to make contact with the resistance 45 which in turn has connection in line 41 in the generator-controller-motor circuit. In other words, the relation between the lever 43 and the resistance 4i, and the effect on the generator-motor circuit is the same here as the relation of the contactor 3l and cooperative resistanoe of the controller I3 in Fig. l, and effect of the controller on the generator-motor circuit of Fig. l. The proportion and arrangement of the parta in Fig. 2 is such that the lever 43 does not make contact with the resistance 46 until.v

after the clutch C is engaged. f'

Operation of .the arrangement of Fig. 2 will thus be as follows, commencing with the parts in the positions indicated, the clutch C' disengaged by its lever 40 and the motor disconnected from the generator by the lever 43 removed from the resistance 46; and otherwise assuming the parts as in Fig. l.

The engine running at its xed speed and the reverse gear R set in forward` or reverse position, manipulation of the lever 43 downwardly, Fig. 2, first releases the movable clutch member to the action. of spring 42 and permits engagement of the clutch. Since the motor M as secured against reverse rotation by the overrunning clutch I4, the load shaft I2, through the reverse gear R, will have drive at reduced speed by way of the dierential D, and this drive will be positive and in fixed ratio with engine speed. as before described in connection with Fig. l. `Such conditions will prevail until the operator advances the lever 43 onto the resistance 4I. 'I'his will not affect the clutch, which is engaged. but will cut the motor M into circuit with the generator G, subject to the resistance 46. 'I'he motor will thus be caused to drive its differential input element at slow speed, but nevertheless the differential D will, in effect, add such speed to that at which the shaft I2 was rotated before, when only the clutch C was engaged. Further advance of the lever 43 to eventually cut out all of the resistance 4i and place the motor directly across the generator to receive the full output of the latter, will, by speeding up the,

motor M, ultimately cause the corresponding differential input element 1 t6 revolve at the same speed as the engine E, at which time the load shaft I2 will be driven at the same speed.

Thereafter, adjustment of the lever 43 in the opposite direction will first cut corresponding parts of the resistance 43 into the motor circuit, causing the load to be driven at correspondingly reduced speeds. Still further motion of the lever will first stop the motor M and then release the clutch C and bring the load shaft I2 to a standstill.

As stated, with the arrangement of Fig. 2 the `engine E is preferably governed as to speed as by a governor such as that shown at 25 and throttle at 26, Fig. 1; in which event, all that the operator need do to control the speed of the load shaft I2, and thus that of the vehicle, if the device be applied to a vehicle, is to adjust the lever 43 to give him the desired speed. It will be observed that in general the arrange ment of Fig. 2 is comparable with that of Fig. 1, the significant differences being two only, first that, in Fig. 2, setting of the motor controller is manual instead of automatic as before, so that the speed of the motor is directly controlled by the operator; both the clutch and the motor controller have a common operator-operated member for their control; and the engine speed is maintained constant.l

With reference now to Fig. 3, the principal parts, comprising the engine E, generator G, clutch C, differential D and motor M, are prent as before, and their arrangement and relation are also as before, except as hereinafter noted, to drive the load shaft I2. The connection of the motor with the generator is subject to a con troller 5l having a contactor arm 5I adjustable over a resistance S2, as indicated. The control arrangement is such that the contactor il, even in its lowest speed position, which is that shown, makes contact with the resistance 52, so that so far as this controller is concerned, the motor M is always inserted with the generator G. How ever, that the connection between the motor and generator be also dependent upon the clutch C, switch means are provided in the generatormotor circuit and arranged to be closed only during engagement of the clutch C. Such switch means are here indicated as Contactors 53A arranged to be bridged by the clutch control lever 54 when the latter is shifted to engage the clutch. The arrangement is such that when the clutch control lever 54 is shifted to disengage the clutch, which is the position in which these parts are shown, the generator-motor circuit will be open between the Contactors 53.

A governor 55 similar to governor 21, is arranged to be responsive to the speed of the load shaft I2, as by connection 56, and has actuating connection, as indicated at 51, with the contactor lever 5I of the controller 50; the proportion and arrangement of the parts being such that when the load shaft I2 is stationary, the governor 55 will automatically position the contactor arm 5| to maintain all of the resistance 52 in circuit, and when the shaft I2 is running at the maximum speed of the engine E, which is assumed to be limited by a' governor as indicated at 58, the contactor arm 5I will be positioned at the opposite end of the resistance 52 to complete the motor circuit without the resistance; intermediate speeds of the shaft I2 producing corresponding intermediate settings of the contactor arm 5I.

The operation of the modification of Fig. 3 will be as follows, assuming the engine operating at the speed permitted by its governor 58 and the clutch C disengaged. No parts of the dif'- ferential are in motion and the load shaft I2 is stationary or without drive. To start driving the load, the operator simply shifts the clutch control lever 54 to engage the clutch C and complete the circuit of the motor M by closing the circuit between the Contactors 53. Engagement of the clutch C causes actuation of the input element 3 of the differential D coincidentally. The load shaft I2 being stationary and presumably connected with a load; its tendency is to resist actuation ofthe output element 4 of the differential, and consequently the other differential input element 1 tends to drive the motor M backwards.

However, coincidental with engagement of the clutch C, the motor is connected in circuit with the generator G, the circuit including all of the resistance 52. The proportion and arrangement of the parts is such that under these conditions the torque of motor M will providesuiiicient braking power against being driven by its differential input element 1, that the element 1 is either held substantially stationary or backed against the motor at a reasonably low speed. In any event, with the described forces on the two input elements 3 and 1 of the differential, the output element 4 will be driven in the ahead direction, to set the load shaft I2 into motion.

As the speed of the load shaft increases, the governor 55 shifts the contactor arm 5I of the controller 50 to cut out resistance 52 proportionally with the speeding up of the load shaft; until ultimately, if sufficient engine speed be maintained, all of the resistance is out of the motor circuit, and the motor is directly across the generator line. Meanwhile the motor armature.

ystarting with its backward operation, hasrst come to a standstill and thence come to such a running speed in ahead direction that its differential input 1 is driven ahead at substantially the speed of the other differential input element 2. Thus all of the differential parts have the same speed, namely that of the engine, as does the load.

To educe the load speed, the engine speed is reduced by closing the hand throttle I6 as necessary.

To stop the load, the operator simply shifts the lever 54 to release the clutch C and open the circuit'at 53. By this operation, drive of both input elements of the differential is terminated and the load shaft consequently still at a standstill. i

With reference now to the modification of Fig. 4, the arrangement generally follows that of Fig. 3 withv the exception that the control of the motor M is had indirectly, through control of the generator output. The generator G has an associated controller 60 for adjustment of its shunt field exitation, by which the generator output is controlled as well understood in the art. The motor M has direct connection with the' generator through a circuit which in itself has no immediate control, the control being wholly in the low voltage field circuit.

The setting of the generator field controller 60 may be by hand, but is here shown as controlled by a governor 6I similar to governors 21 and 55, responsive to the speed of the load shaft l2, as by connection 62, and associated with the contactor of the controller 60, as by connection 53. The controller 50 is unable to open the circuit in which it is arranged, but merely controls how much, if any, resistance is in the circuit. A

Contactors 64 are arranged in the generatormotor circuit to be bridged to complete the motor circuit dependent upon the position of the lever 55 which controls the clutch C, all as more fully described in connection with Fig.` 3. The controller 60 being arranged for automatic operation by the governor 6I., the engine E is provided with a hand throttle IB.

Operation, so far as the operator is concerned, is exactly as in the arrangement of Fig. 3. Start and stop of the load shaft I2 is controlled wholly by manipulation of the clutch control lever 65; and ultimate speed of the load, once started, is controlled by the engine. Acceleration of the load up to the speed permitted by the engine, is wholly automatic; and the speed to which the load will-be accelerated and the rate of acceleration, depends of course upon the amount of the load as well as the engine speed. The greater the engine speed, the greater will .be the load speed attained, but the greater the load the less will be the speed attained.

In the embodiments of both Figs. Sand 4, the control of coupling between generator and motor is automatic, and that of the engine is by hand. An alternate arrangement would. be, following that shown in Fig. 2, providing a fixed engine speed by governor control, and hand setting of the electrical control between motor and 'generator. Such choice would similarly be available in the embodiment of Fig. 1.

In fact, such choice will be dictated by the installation to which the invention is applied. In general, where great loads are to be driven at `low speeds, as in heavy-duty slow moving vehicles, it may usually be preferable toemploy hand control of the generator-motor drive, and governor control of the engine to maintain its speed constant. correspondingly, where light loads are to be driven at high speeds and particularly with maximum rate of acceleration, as

in pleasure automobiles, it will be preferable that the electrical connection between generator and motor be automatically controlled respcnsive to the speed of the load as hereinbefore described, and the engine speed, and consequently the running speed of the vehicle, be controlled by adjustment of its throttle at the will of the operator as by the usual accelerator pedal.

Also, the low voltatge control of. the generator-motor connection by control of the generator iield, with direct high voltage connection between motor and generator, as illustrated in Fig. 4, might be substituted in the arrangements of Figs. 1 and 2 similarly as Fig. 4 shows it substituted for that in Fig. 3.

What I claim is:

l. In combination with an engine, a genera.-v

tor driven thereby, a motor arranged to be driven by the generator, means for controlling the drive of said motor from said generator, diil'erential means having an output element and a pair of input elements arranged for differential drive thereof, means for driving one of said input elements .from said engine, a driving connection from said motor to the other of said input elements. and means independent of the motor driving connections, for automatically opposing drive of said motor-driven input element by either of the other differential elements.

2. In combination with an engine, a generator driven thereby, a motor arranged to be driven by the generator, means for controlling the drive of said motor from said generator, differential means having an output element and a pair of input elements arranged for diilerential drive thereof, means for driving one of said input elements from said engine and including clutch means, a driving connection from, said motor means to. the other of said input elements, and means independent of the motor driving connections, providing that opposition to drive of said motor driven input element by the other differential elements shall automatically follow engagement of said clutch means.

3. In combination with an engine, a generator driven thereby, a motor arranged to be driven by the generator, means for controlling the drive of said'motor from said generator, dierential means having an output element and a pair of input elements arranged for differential drive thereof, means for driving one of said input elements from said engine, a driving connection from'said motor means to the other of said input elements. and means independent of the motor driving connections, for automatically opposing drive of said motor driven input element in reverse direction by the other differential elements- 4. In combination with an engine, a generator driven thereby, a motor arranged to be driven the motor driving connections, associated with*y said motor driven input element to prevent its drive in reverse direction by the other differential elements.

5. In combination with an engine, a generator driven thereby, and a. motor arranged to be driven by the generator, diierential means having a pair of input elements and anoutput element arranged to be differentially driven thereby, means for driving one of said input elements fim said engine and including clutch means, a driving connection from said motor means to the other input element, means for controlling the drive of said motor by said generator, and means associating said clutch means with said controller and providing that power be supplied said motor from said generator automatically upon engagement of said clutch means.

6. In combination with an engine, a generator driven thereby, a motor arranged to be driven by the generator, differential means having a pair of input elements and an output element arranged tov be differentially driven thereby, means for ldriving one of said input elements from said engine, said motor means being arranged to drive the .other of said input elements, means preventing drive of said motor by said engine by way of said diil'erential means, means for controlling the drive of said motor vby said generator, and means for operating said controlling means responsive to the speed of said output elementand arranged to deenergize said motor at output element speeds below a predetermined minimum.

7. In a vehicle having engine means and traction means to be driven thereby, generator means driven by said engine means, motor meansarranged to be driven by said generator means, dierential drive means for said traction means arranged in differentially driven relation with said engine means and with said motor means, and means independent of the motor driving connections, for automatically opposing drive of said motor means through said diierential drive means coincident with drive of said differential drive means from said engine means.

8'. In a vehicle having engine meansand traction means to be driven thereby, generator means driven by said 'engine means, motor means arranged to be driven by said generator means, differential drive means for said traction means arranged in diierentially driven relation with said engine means and with said motor means, and means independent of said generator means and of the motor driving connections, for preventing drive of said motor means through said differential drive means.

9. In a vehicle having engine means and traction means to be driven thereby, generator means driven by said engine means, motor means arranged to be driven by said generator means, means for controlling said motor drive, differential drive means for said traction means arranged in differentially driven relation with said engine means and with said motor means, means providing drive of said traction means from said differential drive means, means for adjusting said controller means automatically responsive to the speed of said traction means, to permit said motor drive only at vehicle speeds above a predetermined and means for opposing drive of said motor by said engine through said ditferentialdrive means.

10. In a vehicle having engine means and traction means to be driven thereby, generator means driven by said engine means, motor means arranged to be driven by said generator means, means forocontrolling said motor drive, differential drive means for said traction means arranged in differentially driven relation with said engine means and with said motor means, clutch means for controlling the engine drive of said diierential drive means, means for adjusting said motor controller means automatically responsive to the speed of said traction means, and means interassociating said clutch means with the motor circuit to cause motor energization substantially coincident with clutch engagement.

11. In combination with an engine, a generator driven thereby, a motor arranged to be driven by the generator, means for controlling the drive of said motor from, said generator, differential means having an output element and a pair of input elements arranged for dinerential drive thereof, means for driving one of said input elements from said engine, a driving connection from said motor to the other of said input elements, and means independent of said generator and of the motor driving connections, for automatically opposing drive of said motordriven input element by the other diierential elements.

12. In combination with an engine, a generator driven thereby, a motor arrangedfto be driven by the generator, means for controlling the drive of said motor from said generator, differential means having an output element and a pair of input elements arranged for differential drive thereof, means for driving one of said input elements from said engine, a driving connection from said motor to the other of said input elements, and means independent of electrical coupling between said generator and said motor and independent of the motor driving connections, for automatically opposing drive of said motor-driven input element by the other differential elements.

13. In a vehicle having engine means and traction means to be driven thereby, generator means driven by said engine means, motor means arranged to be driven by said generator means, differential drive means for said traction means arranged in differentially driven relation with said engine means and with said motor means, and means independent of the motor driving connection, for preventing drive of said motor means through said diierential drive means coincident with drive of said differential drive means from said engine means.

14. In a vehicle having engine means and traction means to be driven thereby. generator means driven by said engine means, motor means arranged to be driven by said generator means, means for controlling said motor drive, diierential drive means for said traction means arranged in diierentially driven relation with said engine means and with said motor means, clutch means for controlling the engine drive of said differential drive means, and means interassociating said clutch means with the motor circuit to cause motor energization substantially coincident with clutch engagement.

15. In combination with an engine, a generator driven thereby, a motor arranged to be driven by the generator, means for controlling the drive of said motor from said generator, differential means having an output element and a pair of input elements arranged for differential drive thereof, means 'for driving one 0i said input elements from said engine, a driving connection from said motor to the other of said input elements, and one-Way clutch means arranged to prevent drive of said motordriven input element by the other differential elements.

16. In combination with an engine, a generator driven thereby, a motor arranged to be driven by the generator, means for controlling the drive of said motor from said generator, diierential means having an output element and a pair 0f input elements arranged for diil'erential drive thereof, means for driving one of said input elements from said engine, a driving connection from said motor to the other of said input elements, and a one-way clutch associated with said motor to prevent its drive by its input element in reverse direction.

y 17. In combination with an engine, a generator driven thereby, a motor arranged to be driven by the generator, means for controlling the drive of said motor from said generator, differential means having an output element and a pair of input elements arranged for differential drive thereof, means for driving one of said input elements from said engine, a driving connection from said motor to the other of said input elements, and a one-way clutch associated with said differential means to prevent drive of said motor-driven input element by the other differential elements.

FRANK R. HIGLEY. 

